@Nordic Norm To answer your question I don’t think that would be an effective solution to expel and eliminate all of the moisture from an HPA/SCBA tank. The goal is to fill them with dry compressed air. Also cracking the valve on your tank lowers your tank’s internal pressure so you’re essentially wasting air unnecessarily. If you have a quality compressor then wasting air is the least of your concerns. But if you’re worried about moisture in your tank, that says to me that you’re using a low-quality compressor. I would think that wasting air will only put extra wear and tear on a low-quality compressor.
I am using inline air dryers and stopped to drain the air/oil seperater on the compressor several times filling an empty 6.8litre tank to 250bar.I am adding an intake air dryer before nest fill. Im confident the tank is dry now. I'm thinking of a way to check for moisture without letting all the air out. The compressor is a little Tuxing. Took 4 1hour runs. Max temp on gauge at 250bar was 42°c drawing 40°f intake air. My theory is heat is what kills these little aircooled rigs.
I am thinking of testing for moisture without letting all the air out of the tank more than anything
It isn't a problem now. I was thinking of a way to test for water without letting all the pressure out. Your method of drying a tank is a good one. Testing with 150bar remaining would probably work without cooling the tank.
This hpa business is new for me. I am naturally cautious and suspicious. I like to stay ahead of any potential troubles. There was a very small amount of moisture at the compressor outlet bleed and a small amount from the air/oil separator. I have learned to construct an intake air dryer using silica beads that change color when saturated. If this causes excessive heat in the compressor, then I can pressurize the intake with my air tool compressor.
Dave, high or low quality compressor has no bearing on whether or not there is moisture. Anytime a gas is compressed it creates adiabatic heating, which causes moisture to condense, an unavoidable characteristic. That's why EFFECTIVE filtration is so important. It's NOT what one PAID for a compressor that mitigates creating of moisture.
I used 300 bar hpa tanks in the fire department years ago. A huge Posidion compressor. It would fill thos bottles so fast they had to be immersed in water to prevent overheating! Slow is definitely the way to go. Unless a cascade system is nearby.
@Gerry52 understood. The assumption in my statements is that a decent compressor will have a good filter. Maybe I should have stated that part in the beginning. In my mind I was thinking the types of filtration systems and media that comes with something like an Alkin compresor versus the filters that people piece together for a Yong Heng type of compressor. Obviously the YH’s work for some people, BUT those folks have found a filtration system and maintenance schedule that works to avoid allowing moisture through to their tanks. At least this has been my assumption. I could be wrong in my assumption. Beyond that I defer to you all for providing better details to the OP.
Understood. Anybody with a YH who doesn't add extra filtration is asking for trouble. Having worked with this stuff for years I knew my 1st task with my YH was to make sure my filtration was taken care of (but I still wish I could afford an Alkin or some such!).
Please elaborate on the nitrogen option. Will a gas supply shop fill a DOT rated non scba hpa tank with nitrogen?
